Which plant structures are the MOST efficient means of plant dispersal on land?

thank you so much for you help. if you dont know all answers, answering a few will be amazing too

1. Which plant structures are the MOST efficient means of plant dispersal on land?
a       fruits with seeds
b       masses of pollen
c       swimming sperm
d       windborne spores
 
   
2. Which is a definitive reason why porpoises are considered mammals?  
a       They breathe with lungs.
b       They have mammary glands.
c       They lay eggs on the bottom of the ocean.
d       They are warm-blooded.
 
   
3. Which class of fish has the most species?  
a       bony fish
b       cartilaginous fish
c       jawless fish
d       lungfish
 
   
4. ______________ tissue is the most abundant and diverse of the four types of tissue.  
a       Muscle
b       Neural
c       Fat
d       Connective
 
   
5. Which is NOT a characteristic of most vertebrates?
a       two sets of paired appendages
b       an open circulatory system
c       a spine
d       gills or lungs