From the given alternatives, select the word which CANNOT be formed using the…

The letters available in PERMANENT are: P, E, R, M, A, N, T — with E appearing twice and N appearing twice (P-E-R-M-A-N-E-N-T).

Check each option against this letter inventory:

REMNANT uses R, E, M, N, A, N, T — it needs N twice, and PERMANENT has two N's, so every letter is available.

TRAMP uses T, R, A, M, P — all of these letters are present in PERMANENT.

MENTOR uses M, E, N, T, O, R — it requires the letter O, but there is no O in PERMANENT, so this word cannot be formed.

AMPERE uses A, M, P, E, R, E — it needs E twice, and PERMANENT has two E's, so every letter is available.

Hence MENTOR is the word that cannot be formed from the letters of PERMANENT.