Bob, a widower who is $65$ years old, has correctly calculated his taxable income for $2022$ as follows:

Employment income under Subdivision a $$10,000$

Pension income $($registered pension plan$)20,000$

Old Age Security and Canada Pension Plans $10,000$

Dividends from Canadian$-$resident public corporations $($grossed up$)5,520$

Interest income $5,000$

total $$50,520$

What is the maximum amount $($rounded to the nearest dollar$)$ of federal income tax credits that Bob can claim on his $2022$ tax return?a$)4154$

b$)4660$