单项选择题

Life expectancy among adults 45 and 65 years of age by family income, sex, and race: United States, average annual 1979-89.

A sequence of numbers begins 1, 1, 1, 2, 2, 3 and then repeats this pattern forever. What is the sum of the 135th, 136th, and 137th numbers in the sequence?()

A.3
B.4
C.5
D.6
E.7