Final answer:
The most reasonable estimate for the product of 2.8 x 35 is 100, since rounding 2.8 to 3 and multiplying by 35 gives an estimated product close to 105.
Step-by-step explanation:
To estimate the product of 2.8 x 35, we can round 2.8 to the nearest whole number, which is 3. Multiplying 3 by 35 gives us 105. However, this product is not one of the answers provided. Looking at the choices given, the closest and most reasonable estimate would then be 100 (option C), which is slightly less than our estimated product of 105. Option A (70) is too low, B (75) is also too low considering 2 x 35 already gives 70, and D (120) is higher than our estimated product.