The question lacks the diagram. The diagram has been attached below.
Answer:
1.
Explanation:
Exons may be defined as the coding region of the RNA whereas introns are the non coding region of the RNA. The introns must be removed out from the RNA to makes it functional molecule.
The splicing of the given molecule results in the formation of single mRNA. The 1 splicing of the introns remove intron A whereas the second splicing results in the removal of intron B. The functional mRNA consists of the mRNA with exon 1,2 and 3.
Thus, the answer is 1.
