Answer:
The correct answer is option b.
Step-by-step explanation:
Changing oil is a service. Susan used to go to Speedy lube for changing the oil. She used to pay them in return for their service. This payment was included in GDP. But Susan switches from going to Speedy Lube for an oil change to changing the oil in her car herself.
When Susan is changing oil herself this will not be included in the GDP as she is doing it for herself and no one is paying her for it.