Two Rockets, a and B, Approach Each Other as Shown

Multiple Choice

Two rockets, A and B, approach each other as shown in the figure. A travels to the right at 0.7c while B travels to the left at 0.8c. Both speed measurements are made relative to an inertial observer.
-Both rockets have a supply of unstable mesons with a mean proper lifetime of 2.6 × 10^-8 s. Which one of the following is a correct observation for the inertial observer?

A) The mesons in A have a mean lifetime of 4.3 × 10^-8 s.
B) The mesons in B have a mean lifetime of 3.6 × 10^-8 s.
C) The mesons in both rockets have a mean lifetime of 2.6 × 10^-8 s.
D) The mean lifetime of the mesons is the same for both rockets, but less than 2.6 × 10^-8 s.
E) On average, the mesons in A will decay before the mesons in B.