Vaping Electronic Cigarettes, or E-Cigarettes, Are Electronic Devices That Provide Users

Vaping
Electronic cigarettes, or e-cigarettes, are electronic devices that provide users with the same nicotine "fix" that they would receive from a traditional cigarette. However, e-cigarettes do not burn tobacco, and thus do not produce the same toxic chemicals as traditional cigarettes. For this reason, many believe that using e-cigarettes (also known as "vaping") is a safe alternative to smoking tobacco. This perception has turned vaping into a billion-dollar industry and has made vaping extremely popular, especially among adolescents. However, even though e-cigarettes do not produce tobacco smoke, they are still not completely safe.
E-cigarette vapor contains a variety of toxic chemicals, including formaldehyde and acetaldehyde. Although they are harmless in small amounts, there have not been any studies of the dangers of long-term exposure to these chemicals. Furthermore, the nicotine in e-cigarettes is just as addictive as the nicotine in traditional cigarettes. Withdrawal symptoms from nicotine deprivation include mood swings, anxiety, and changes in appetite. Exposure to nicotine can also be dangerous for people with cardiovascular problems.
While vaping may be better for you than smoking traditional cigarettes, more research needs to be done before e-cigarettes can be considered completely safe. People-especially adolescents-should be wary of getting hooked on these "harmless" cigarettes.
Question: Which supporting detail is an example of an opinion, rather than factual information?

A) In terms of its addictive properties, the nicotine in e-cigarettes is similar to that in normal cigarettes.
B) Exposure to nicotine can be dangerous for those with compromised immune systems.
C) Vaping has become a billion-dollar industry, partly due to the fact that it is considered as a safe alternative to traditional smoking.
D) In all cases, it is a bad idea to become addicted to vaping.