Sentence Correction (SC) | Re: Despite last minute efforts by the company's design team at improving

Despite last minute efforts by the company's design teamat improving it, the gas-guzzling SUV, continuing its decline in the market, production ceasing at the end of the decade.

a) at improving it, the gas-guzzling SUV, continuing its decline in the market, production ceasing

b) at improving it, the gas-guzzling SUV continued its decline in the market, to cease production

c) at improving it, the gas-guzzling SUV continued declining in the market, and production was ceased

d) to improve it,