According to data, approximately 47.6 million Americans experience some form of mental disorder in 2018. This is a very huge number; to put into perspective, the population of America, in 2018, was roughly 327.2 million. This means that 19.1% of U.S. adults, i.e. 1 in 5 adults, experienced mental illness in 2018. Hence, the closest option to the real statistics is option (b): more than 50 million
To keep his chin up and to continue to work on his grades in order to bring happiness to the house. Seeking a relative or close friend for support would also be the best option in pushing through these tough times.