A bottle contains a label stating that it contains Spring Valley pills with 500 mg of vitamin C, and another bottle contains a label stating that it contains Merck pills with 40 mg of lisinopril that is used to treat high blood pressure. Identify which one of the following errors is most serious, explain why it is most serious, and characterize the error as being a type I error or a type II error. 

i. For lisinopril, fail to reject H₀: μ = 40 mg when the mean is actually different from 40 mg.

ii. For lisinopril, reject H₀: μ = 40 mg when the mean is actually equal to 40 mg.

iii. For vitamin C, fail to reject H₀: μ = 500 mg when the mean is actually different from 500 mg.

iv. For vitamin C, reject H₀: μ = 500 mg when the mean is actually equal to 500 mg.