The figure shows the motion of a planet around the sun in an elliptical orbit with the sun at the focus. The shaded areas $A$ and $B$ are also shown in the figure,which can be assumed to be equal. If ${t_1}$ and ${t_2}$ represent the time taken for the planet to move from $a$ to $b$ and $d$ to $c$ respectively,then:

• A
  ${t_1} < {t_2}$
• B
  ${t_1} > {t_2}$
• C
  ${t_1} = {t_2}$
• D
  ${t_1} \le {t_2}$