In the following passage some words have been deleted. Fill in the blanks with the help of the alternatives given. Select the most appropriate option for each blank.

Comprehension:
M. Ananda Kumar, scientist, Nature Conservation Foundation says that elephants are "engineers of the eco-system. He explains : they are seed (1)_____ . Forests without (2)_____ have been observed to not have young (3)_____ at all. This is because (4)_____ species disperse seeds only through elephants." The animals are phenomenal at (5)_____ themselves to new ecological conditions and negotiating a problem.