I think it might be B, not 100%
Answer:
The fraction of blue shirts that she sold is 
Step-by-step explanation:
She sold:
1/3 on Tuesday.
5/12 on Wednesday.
What fraction of blue shirts did she sell on Tuesday and Wednesday?
Sum of fractions.
The lesser common multiplier between 3 and 12, which is 12.
So

The fraction of blue shirts that she sold is 
-3 + -2 = -5
-5 + 5 = 0
0 x 2 = 0