Answer:
Option A is the right answer.
Step-by-step explanation:
Given information is:
The profit on the sandwiches is $2 for chicken salad and $3 for roast beef.
The amount of bread available is enough for 30 sandwiches.
If chicken salad sandwiches take 3 minutes to prepare and roast beef sandwiches take 5 minutes.
Let x represent the roast beef sandwiches.
Let y represent the chicken salad sandwiches.
The system of equations becomes:
or
..... (1)
....(2)
Substituting (1) in (2)





y = 15
As
so, 
x = 15
Now we will see the profit;
P =
dollars
Therefore, 15 roast beef sandwiches and 15 chicken salad sandwiches should be prepared to maximize the profit.
Hence, the answer is option A.