The Decomposition of an Aldehyde Solution in Carbon Tetrachloride Is

The decomposition of an aldehyde solution in carbon tetrachloride is a first-order reaction with a rate constant of 1.20 × 10^-3 min^-1. If we start with [aldehyde] = 0.0500 M, what will the concentration of aldehyde be 150 minutes later?

A) 0.00900 M
B) 0.0418 M
C) 0.00926 M
D) 0.00499 M
E) 0.000333 M