In Mollusca ,
I. digestive tract is a complete and complex with ciliary tracts for sorting small particles .
II.shows caste system .
III.has a pair of respiratory trumpets .
IV.are blood suckers of vertebrates .
Choose the correct option .
A. Statement I and III are correct
B. Statement I and II are correct
C. Statement I , II and IV are correct
D. Only statement IV is correct
