Examine the figure given below and select the right option identifying all the four parts $a, b, c$ and $d$.

• A
  $a$: Endothecium, $b$: Tapetum, $c$: Microspore mother cell, $d$: Middle layers
• B
  $a$: Tapetum, $b$: Endothecium, $c$: Microspore mother cell, $d$: Middle layers
• C
  $a$: Endothecium, $b$: Middle layer, $c$: Tapetum, $d$: Microspore mother cell
• D
  $a$: Endothecium, $b$: Microspore mother cell, $c$: Middle layer, $d$: Tapetum