Keyboarding ability is an important skill now of even senior-level man

Official Explanation:

Read the Original Sentence Carefully, Looking for Errors:

Sometimes the best way to work out how modifiers should operate in a sentence is simply to read the sentence for sense and clarity. The best solution will be the simplest statement of the meaning—and this happens when the adverb “now” is close to what it modifies, the verb “is.”

Scan and Group the Answer Choices:

(B) and (C) place “now” at the end. (A) and (E) place “now” near the middle of the underlined portion. Only (D) places “now” near the beginning of the underlined portion, next to "is."

Another way to group the choices is to see that (A), (B), and (C) use the word "skill" while the other two answers do not. Because the word "ability" is provided in the non-underlined portion, stating that keyboarding is a "skill" is redundant.

Eliminate Choices Until Only One Remains:

Knowing that the modifier must be as near as possible to what it modifies, look at where the modifier appears in each choice. Eliminate (B) and (C) because the modifier is at the end of the underlined portions.

(A) and (E) can also be eliminated because they place the modifier too far from what it modifies.

(D) is correct because the modifier is right next to what it modifies. If you eliminated (A), (B), and (C) because they used the excess word "skill," then note that (E), by using the phrase "even now" suggests that keyboard is still an important skill after having also been important in the past, but the original sentence implies no such thing.

TAKEAWAY: Make sure adverbs are placed as close to the verb they modify as possible.