According to the passage, the Thync package______.

单项选择题

Feeling stressed out or in need of a boost Soon you may be able to turn to your smartphone for help. American tech company Thync this week released a smartphone-controlled headset which can alter users’ moods by stimulating nerve endings on the skin. The Thync package, which costs $ 299 and is currently only available in the US, consists of a small, triangular shaped headset, five adhesive strips which stick it to the user’s foreheads, and a downloadable iPhone app, which controls the headset via bluetooth radio. Designers say the headset uses a process called "neurosignalling", which stimulates the skin on the forehead and neck using tiny pulses of electricity, arousing nerve endings which then supposedly activate a change in user’s brain activity and overall mood, thus creating a state of calm or a boost of energy. The time this takes depends on the user’s preference as they can choose the intensity of their session. Dr. Jamie Tyler, founder and chief scientific officer at Thync, told Newsweek "Thync combines what we know about modern neuroscience and how it works with modern consumer technology to help people to relax or give them a little boost of motivation." Tyler says Thync is aimed at "healthy adults who want a different tool to gain more energy or relaxation in their day". However, Emiliana Simon-Thomas, science director of the Greater Good Science Centre at the University of California at Berkeley has raised questions about the safety of the device, emphasising the possibility of negative, long-term side effects. "At what point does it become something that your nervous system adapts to We don’t know the longitudinal impact," she told Buzzfeed, adding that she would not use the device. Thync’s website says the device is a "low-risk transdermal(穿过皮肤的)neurostimulation device", claiming it has been tested in a number of single-blind and double-blind placebo-controlled studies on over 3 500 users without "significant" side effects. Tyler adds that the technology behind Thync "is very similar to the technology used to treat pain via electrical muscle stimulation". Early reviews have been mixed. TechCrunch’s Kyle Russell noted experiencing tingling sensations around his temples and forehead, and found the device so effective when testing it out, that he experienced difficulty constructing a coherent sentence when trying to speak to onlooking Thync staff. Buzzfeed’s reviewer claimed the device caused her forehead to throb and ache when cranked up to 50%. For now, the product is only available in two modes: calming and energizing. However Thync designers are working on other, newer technologies which will be ready for release next year and while the headset is currently only available in the US currently, Tyler confirmed that expanding the Thync brand to Europe is on the company’s radar.

A．is now only available in North America
B．can only work together with an iPhone
C．possesses much better tone quality than most headsets
D．is developed with the help of Apple technicians