Final answer:
B) 3
After analyzing numbers from 3 to 87, the least digit among those divisible by 4 with a sum of digits equal to 9 is 4 which is found in the number 45. Hence, option B) 3 is incorrect as the correct answer is not listed in the provided choices.
Step-by-step explanation:
The question asks to find the least digit among numbers from 3 to 87 that are divisible by 4 and have a sum of digits equal to 9. Firstly, let us list numbers divisible by 4 in this range: 4, 8, 12, 16, 20, ..., 84. Now, we need to find the ones with sum of digits equal to 9. Essentially, we are looking for two-digit numbers since 3 through 8 do not satisfy being divisible by 4 and having digit sums of 9.
Examining the numbers divisible by 4, we notice that 40 is the first one in the list where the sum of digits is 4 (4+0). To reach a sum of digits equal to 9, adding 5 to 4 is necessary. Thus, 4 + 5 = 9, and the respective number should be 4 followed by 5. Hence, 45 is the smallest number divisible by 4 and with a sum of digits equal to 9. Examining the number 45, we have two digits: 4 and 5. Therefore, the smallest digit is 4, which matches with option B) 3 from the provided choices.