Given below is the diagram of a bacteriophage. In which one of the options are all the four parts $A, B, C$ and $D$ correctly identified?

• A
  $A$-Tail fibres,$B$-Head,$C$-Sheath,$D$-Collar
• B
  $A$-Sheath,$B$-Collar,$C$-Head,$D$-Tail fibres
• C
  $A$-Head,$B$-Sheath,$C$-Collar,$D$-Tail fibres
• D
  $A$-Collar,$B$-Tail fibres,$C$-Head,$D$-Sheath