While Margot was home with the children, Craig deposited $$4000$ into a spousal RRSP for Margot in $2015,$ $$4000$ in $2016,$ $$5000$ in $2017$ and $$5000$ in $2018.$ These are the only deposits he made to her spousal RRSP$.$ They withdrew the $$15000$ from Margot's spousal RRSP in $2019.$ A$)$ Craig will have to pay tax on what amount? $($$$10,000)$ B$)$ Margtw$5$ill have to pay tax on what amount? $($$$5,000)$ I need explanation pls$.$