Previous Year Questions

'And discovering that there are' would replace the highlighted phrase because -ing form of verb 'discovering' would be correct to be in uniformity with another -ing form of verb 'demanding' as both are connected with the conjunction 'and', but 'discovered' is the past tense/participle. Similarly, options (a) and (c) can be eliminated because 'discovers' is the third person present. Option (b) is incorrect because singular verb 'is' cannot be used with plural noun phrase 'easy ones'.

Hence, option (d) is correct.