The write-off of an uncollectible account has which of the following effects on net income and net realizable value?

a. No effect on net income and no effect on net realizable value

b. Decrease on net income and no effect on net realizable value

c. No effect on net income and a decrease in net realizable value

d. Decrease in net income and a decrease in net realizable value

e. None of the above

Please help to explain for my better understanding.