What occurs when the cell uses oxygen for respiration

Would really appreciate it, i have an idea but not completely sure

Which strategy is an example of how companies may upgrade themselves to meet changing customer preferences? a. doing door-to-door sellingb. using billboards to advertise the productsc. making online shopping services availabled. giving discounts on products

Which worm has eyespots that are used to detect light? a fluke b marine worm c planarian d tapeworm