What type of feeding mechanism is observed in Cephalochordates?

Which of the following possesses an endoskeleton made of cartilage or bone?

Which of the following is present during some stage of the life cycle in animals belonging to the phylum $Chordata$?

The notochord is an organ derived from which embryonic layer?

Which of the following animals is known as an invertebrate chordate?

Assertion $(A)$: $Ascidia$ and $Salpa$ are placed under sub-phylum $Urochordata$.
Reason $(R)$: In $Ascidia$ and $Salpa$,notochord is present only in larval tail.
In the light of the above statements,choose the most appropriate answer from the options given below: