Omar Is Single, Age 46, and Reported AGI of $126,000

Omar is single, age 46, and reported AGI of $126,000 in tax year 2015. He is an active participant in his employer's pension plan. What is the maximum Roth IRA contribution he can make in 2015?

A) $0.
B) $1,833.
C) $3,667.
D) $5,500.