The correct option is C Monday, August
The date marked in the calendar is the 17th.
At the top of the calendar, we can see the month mentioned is August. So, the calendar shown is for the month of August.
If we map the 17th with the days of the week mentioned at the top of the calendar, we can see that it falls on a Monday.
Therefore, the date marked in the calendar is the 17 August, which is a Monday.