An MRNA 2650 Base Pairs Long Was Transcribed from a Gene

An mRNA 2650 base pairs long was transcribed from a gene containing 3782 base pairs. The most likely explanation would be that

A) the gene sequence was altered and now contains a nonsense mutation.
B) the gene sequence was altered and now contains a missense mutation.
C) splicing during transcription removed introns from the sequence.
D) the gene sequence was altered and now contains a nonsense mutation and splicing during transcription removed introns from the sequence.
E) the gene sequence was altered and now contains a missense mutation and splicing during transcription removed introns from the sequence.