Carol Signed a Contract to Sell Her Rental Property in June

Carol signed a contract to sell her rental property in June 2020 for settlement to take place in December 2020. She will make a net capital gain of $50,000 from the sale of this rental property. In which year will the net capital gain have to be included in carol's assessable income?

A) Carol has a choice as to which year- 2020 or 2021 that she wants to include the net capital gain into her assessable income
B) Carol does not need to include this net capital gain into her assessable income as the rental property is an exempt CGT asset
C) 2020 tax year
D) 2021 tax year