Explanation:

The pardoning power of the President is independent of the Judiciary; it is an executive power. But, the President while exercising this power, does not sit as a court of appeal. The object of conferring this power on the President is two-fold: (a) to keep the door open for correcting any judicial errors in the operation of law; and, (b) to afford relief from a sentence, which the President regards as unduly harsh.
Statements 1 and 3 are correct: Pardon removes both the sentence and the conviction and completely absolves the convict from all sentences, punishments and disqualifications.
Reprieve It implies a stay of the execution of a sentence (especially that of death) for a temporary period. Its purpose is to enable the convict to have time to seek pardon or commutation from the President.
Statement 2 is not correct: Respite denotes awarding a lesser sentence in place of one originally awarded due to some special fact, such as the physical disability of a convict or the pregnancy of a woman offender. Remission implies reducing the period of sentence without changing its character. For example, a sentence of rigorous imprisonment for two years may be
remitted to rigorous imprisonment for one year.