a
As \(-I\)  effect increases, \(COOH\) group becomes more electron deficient and tendency to loose \(H^+\) ions increases i.e., acid strength increases. As \(+l\) effect increases. acid strength decreases. Thus, correct order of acid strength is

\(\mathrm{CF}_{3} \mathrm{COOH}>\mathrm{CCl}_{3} \mathrm{COOH}>\mathrm{HCOOH}>\mathrm{CH}_{3} \mathrm{COOH}\)

\((B) \quad \quad \quad >\quad \quad(A) \quad \quad > \quad(D) \quad > \quad(C)\)