Answer : The correct option is, (D) 89 %
Solution : Given,
Moles of A = 3.0 mol
Moles of B = 2.0 mol
First we have to calculate the limiting and excess reagent.
The balanced chemical reaction is,

From the balanced reaction we conclude that
As, 2 mole of A react with 1 mole of B
So, 3 moles of A react with
moles of B
From this we conclude that, B is an excess reagent because the given moles are greater than the required moles and A is a limiting reagent and it limits the formation of product.
Now we have to calculate the moles of C.
From the reaction, we conclude that
As, 2 mole of A react to give 3 mole of C
So, 3 mole of A react to give
mole of C
Theoretical yield of C = 4.5 mol
Actual yield of C = 4 mol
Now we have to calculate the percent yield of of the reaction.


Therefore, the percent yield of the reaction is 89 %