Modify the statement below to make it a true statement? If a is irrational and b is rational, then a+b is rational.
A. If a is rational, and b is rational, then a+b is rational.
B. If a is irrational and b is irrational, then a+b is irrational.
C. If a is rational and b is rational, then a+b is irrational.
D. If a is irrational and b is irrational, then a+b is rational.