Tobraviruses are transmitted by…….

✅Explanation:
Tobraviruses, a group of plant viruses that include Tobacco rattle virus (TRV) and Pea early browning virus (PEBV), are primarily transmitted by nematodes belonging to the genus Trichodorus. These nematodes are commonly known as stubby-root nematodes.

📌Other Options Explanations:
(b) Xiphinema sp.: Xiphinema species are known to transmit nepoviruses.
(c) Longidorus sp.: Longidorus species also transmit nepoviruses.