The given sentence requires a participle, because the verb phrase is already present in the sentence and is complete: "is drawing up (an economic plan)".
Option D: 'Providing' is a present participle that modifies the phrase "East Timor with a stronger ...". (Participles function as adjectives.)
It completes the sentence in meaning and Grammar, hence option D is correct.
Option A: 'Provide' is a base verb. It does not fit the sentence in meaning as well as structure. It requires a preposition 'to' or a helping verb 'was, were, is, are, etc.'
Option B: 'Provides' is a simple present tense verb but here it does not fit into the sentence. The sentence requires a participle and not a verb.
Option C: 'To provide' is not correct because there's already a preposition 'at'. They don't go together as each has a specific meaning.
Hence options A, B and C are wrong.