Iam offering 15 points for anyone who gets this right!

hannah is showing her work in simplifying (6.1 − 4.5) − 2.5 + 3.9. identify any error in her work or reasoning.

step 1: (6.1 − 4.5) − 2.5 + 3.9
step 2: 6.1 + (− 4.5 − 2.5) + 3.9 (associative property)
step 3: 6.1 − 7 + 3.9
step 4: 6.1 + 3.9 − 7 (distributive property)
step 5: 10 − 7 = 3

a. she wrote distributive instead of associative in step 4.
b. she wrote associative instead of distributive in step 2.
c. she wrote distributive instead of commutative in step 4.
d. she wrote associative instead of commutative in step 2.