The possible four base long sticky end will be AATT or TTAA.
Option C.
Step-by-step explanation:
The restriction endonuclease enzymes are those enzymes which can cut a portion of DNA at specific base pair sequences. This restriction endonucleases sometime cuts the DNA in such a manner that often some of the nucleotides become pairless and remain as lone nucleotides, which are called as sticky ends.
Here, the said restriction endonuclease cuts the DNA at the sequence GTTAAC. If the DNA has a sticky end with 4 sticky nucleotides, then the possible cuts are at the portions G / TTAAC and at C/ AATTG. Here the portion TTAA or the portion AATT remains pairless in the cut portion which is the four nucleotide long sticky base.