Question

which components form the outer
ails\ of a dna molecule? the sugars and phosphate groups the sugars and bases the bases and phosphate groups the complementary bases

Explanation:

In a DNA molecule, the structure is a double helix. The outer "rails" (the backbone) of the DNA are formed by alternating sugar (deoxyribose) and phosphate groups. The bases (adenine, thymine, cytosine, guanine) are the rungs of the ladder, and complementary bases pair in the middle. So the components forming the outer rails are the sugars and phosphate groups.

Answer:

the sugars and phosphate groups