The Tiktaalik Fossil,which Dates Back 375 Million Years,is Considered a Transitional

The Tiktaalik fossil,which dates back 375 million years,is considered a transitional fossil because _____.

A) the species lived while Earth was still forming.
B) it was discovered half in the water and half on land.
C) the organism was swimming when it was crushed by falling rock.
D) it shows the transition between two- and four-legged organisms.
E) it displays features found on both aquatic and land-dwelling species.