Answer: the mutation as a substitution (GAG to CGC) and an addition (T) is more likely than two separate insertions and addition
Explanation:
Taacgagg to taacCgCaggT
? Insertions
gag > cgc + g>gt
? substitution + addition
This could be read as 2 separate insertions and 1 addition, or 1 substitution and an addition