Feeding and Nesting

[hariharakarthi]

Ornithologists find it difficult to study the Amazonian Biffa, a species native to the Amazon watershed, mainly on account of its feeding and nesting at great heights—often 200 to 300 feet above the forest floor.

A. on account of its feeding and nesting

B. on account of their feeding and nesting

C. because it feeds and nests

D. because they feed and nest

E. because of their feeding and nesting

[madhur_ahuja]

C -- species should be singular.

Ornithologists find it difficult to study the Amazonian Biffa, a species native to the Amazon watershed, mainly on account of its feeding and nesting at great heights—often 200 to 300 feet above the forest floor.

A. on account of its feeding and nesting

B. on account of their feeding and nesting

C. because it feeds and nests

D. because they feed and nest

E. because of their feeding and nesting

[arorag]

Mail down to A/C then because is better than on account so C

[shahdevine]

Ornithologists find it difficult to study the Amazonian Biffa, a species native to the Amazon watershed, mainly on account of its feeding and nesting at great heights—often 200 to 300 feet above the forest floor.

A. on account of its feeding and nesting

B. on account of their feeding and nesting

C. because it feeds and nests

D. because they feed and nest

E. because of their feeding and nesting

"on account of" is weak, unidiomatic. eliminate a/b. D has "they" which has unspecified reference pronoun and E also has unspecified reference pronoun. C

[goelmohit2002]

I am down to A and C...but can't decide to choose one over the other for grammtical reason...for concision reason....C looks better....

is there a grammatical reason to choose one over the other ?