Given the task definition and input, reply with output. You are given a math word problem and you are supposed to make use of mathematical concepts like probability, combinatorics, linear equations, sequences/series, or simple operators like addition, subtraction, division, or multiplication to answer the given question. Choose the best option from the 5 given options and report that option.

Question: If 4a = 5b = 30, then 40ab =

 Option A: 900

 Option B: 1800

 Option C: 2250

 Option D: 1650

 Option E: 1250

Option B