Concept:Simple interest is calculated using the formula SI=100P×R×T.Explanation:Here, Principal P=400, Rate R=10% per annum, and Time T=2 years.Substitute these values into the formula:SI=100400×10×2Simplify by cancelling the two zeros in 400 and 100:SI=4×10×2=80So, the simple interest is GH₵ 80.00.Answer:C. GH₵ 80.00