Select the correct statement from the following: 
A. Fleshy cylindrical stem in Euphorbia carry out photosynthesis. 
B. Pistia and Eichhornia are example of offset. 
C. Underground stem of grass and strawberry spread to new niche and when older part die new plants are formed. 
D. Thorns are woody, straight and pointed. 

• A

  A and B only 

• B

  B and D only 

• C

  B and C only 

• D

  A, B, C and D