Which Demographic Groups Are Most Likely to Develop Myasthenia Gravis

Which demographic groups are most likely to develop myasthenia gravis?
1) Females >40 years of age
2) Males <35 years of age
3) Females 15 to 35 years of age
4) Males 40 to 70 years of age

A) 1, 2
B) 3, 4
C) 2, 3
D) 1, 4