Revaluation Question

Herath Construction Ltd has a piece of land on the company’s books valued at £800,000. Five years ago, a boom in land values led the company to increase the carrying value to £880,000. In recent times, however, there’s been a decline in land prices and it is estimated by a surveyor that the land is now worth only £770,000. How should the values be accounted for at the end of the current year? a) Dr revaluation surplus £110,000; Cr non-current asset £110,000 b) Dr income statement £30,000; Cr non-current asset £30,000 c) Dr revaluation surplus £80,000; Cr income statement £50,000; Cr non-current asset £30,000 d) Dr revaluation surplus £80,000; Dr income statement £30,000; Cr non-current asset £110,000 Is the answer D? If so can you demonstrate the calculations? Thank you in advanced.