An example of a mandatory withholding is:

Mandatory payroll deductions are the wages that are withheld from your paycheck to meet income tax and other required obligations

Explanation: Mandatory deductions basically ensure we pay our taxes so as to not be caught up in the reds like many of our celebrity counter parts due to lack of not paying back uncle Sam.

Whereas.. a voluntary deduction would be towards your 401(k) or other retirement fund.

the sentence that contains a restrictive clause is a.they decided to meet where the band was performing

explanation:

a restrictive clause is also known as an essential clause

a line graph will be best to show the income.