$[3$pt$]$ What statement should replace the first line of the code below to avoid error?

age $=$ input$(\text{'}How$ old are you?:$\text{'})$

age $=$ age $+1$

Author: MK$,$ Editor$($s$)$: JFM

a$.$ age $=$ input$($age$)$

cross

b$.$ age $=$ input $(\text{'}$age$\text{'}$