Which condition requires expert medical ? a. first-degree burn on hand b. sprained ankle c. nosebleed d. persistent vomiting

Most likely D because a sprained ankle can be put into a splint which there is most likely someone that can make on. 

It’s D. persistent vomitting

Explanation:

The other guy is useless

I got it wrong, it’s D

Siliceous ooze is a siliceous pelagic sediment that covers large areas of the deep ocean floor. Siliceous oozes consist predominantly of the remains of microscopic sea creatures, mostly those of diatoms and radiolarians. Sometimes siliceous oozes also contain silicoflagellates and the spicules of sponges.