Question 252434
Based on the information, we can write the ratio of side A to side B as 
3/12 = 1/4.

To go from side ratio to area ratio, square the side ratio.

(1/4)^2 = 1/16. This means that triangle B has an area 16 times bigger than the area of triangle A. Since the area of triangle A is 10, 10 * 16 = 160. This is choice [ C ].