Which of the following options contains a set of protochordates?

Step-by-step solution

Subphyla Urochordata and Cephalochordata are often referred to as protochordates and are exclusively marine. In Urochordata, the notochord is present only in larval tail, while in Cephalochordata, it extends from head to tail region and is persistent throughout their life. Examples: Urochordata – Ascidia , Salpa , Doliolum ; Cephalochordata – Branchiostoma (Amphioxus or Lancelet).