Final answer:
Mrs. Pacor has 3 whole pieces of yarn. Therefore, the answer is A) 3.
Step-by-step explanation:
To find the number of whole pieces of yarn that Mrs. Pacor has, we need to divide the total length of the yarn (3 feet) by the length of each piece (1 foot). So, 3 ÷ 1 = 3 whole pieces of yarn. Therefore, the answer is A) 3.