Saponins are:
Correct option is C, Steroid/triterpene glycosides. In PLANT SEC METABOLITES problems like this, the accurate statement is Steroid/triterpene glycosides; the others are common mix-ups. Not these: A) Steroids; B) Sugars; D) Proteins. Tissue transport questions usually turn on xylem vs phloem, living vs dead cells, or source vs sink.
Ref: Best CSIR NET Plant Physiology books: Master Unit 6 with Taiz & Zeiger and Salisbury & Ross. Crack Part C experimental questions with top textbooks.