Fill in the blank with the most appropriate word.

This article is worth ____.

The correct option is C reading

Gerunds are words that are formed with verbs but act as nouns. Gerunds also at times are seen to end in 'ing'. In this particular sentence, the word in the blank acts a noun thus becoming the subject of the sentence and also like a verb by taking up the object. This means that in the blank, we would need a gerund.

Option A: "Reading" is a gerund as it behaves as a noun as well as a verb in the sentence

Option B: "Read" is in the present tense. Option C goes the same way

Option D: "has Read" is in the past tense

Option E: "Will read" is in the future tense.

Option A is correct