Correct Answer: (c) Experts said, "Several steps are being taken to promote foreign trade as it constitutes 45% of the country's economy".
Note: (c) Experts said, "Several steps are being taken to promote foreign trade as it constitutes 45% of the country's economy".(Correct) Said that said Were being → are being
(a) Experts are saying, "Several steps were taken to promote foreign trade as it constituted 45% of the country's economy".(Incorrect reporting verb)
(b) Experts said, "Several steps should be taken to promote foreign trade as they constitute 45% of the country's economy". (Incorrect Tense)
(d) Experts said, "Several steps had been taken for promoting foreign trade as it constitute 45% of the country's economy". (Incorrect Tense)