1.  B2CD, _____, BCD4, B5CD, BC6D

A. B2C2D
B. BC3D
C. B2C3D
D. BCD7

Answer: Option B

Explanation:

Because the letters are the same, concentrate on the number series, which is a simple 2, 3, 4, 5, 6 series, and follows each letter in order.