Answer:
d. $41,000 
Step-by-step explanation:
The computation of the total contribution to profit and overhead is shown below:
Contribution by Business Hotel Customers is 
= Sales - variable cost 
= (100-25) ×280 
 = $21,000 
Now 
Contribution by Convention Association Hotel Customers = Sales - variable cost 
= (75 - 25)× 400 
 = $20,000 
 And, finally
Total contribution to profit and overhead is 
= $21,000 + $20,000 
= $41,000