Select the correct sequence with respect to sewage treatment.
$i$. Removal of suspended solid particles by primary treatment.
$ii$. Wastewater screening
$iii$. Anaerobic bacteria digest activated sludge.
$iv$. Treatment by flocs in aeration tank.
$v$. Grit settling

• A
  $ii \longrightarrow v \longrightarrow iv \longrightarrow i \longrightarrow iii$
• B
  $v \longrightarrow ii \longrightarrow i \longrightarrow iv \longrightarrow iii$
• C
  $ii \longrightarrow v \longrightarrow i \longrightarrow iv \longrightarrow iii$
• D
  $v \longrightarrow ii \longrightarrow iv \longrightarrow i \longrightarrow iii$