OG详解-OG7 文法 Q16

Choice D is the best answer. The convention being tested is the use of verb forms within a sentence. The nonfinite to-infinitive verb “to include” is correctly used to form a subordinate clause that indicates what the Olympic committee decided (to include tug-of-war as an Olympic event). 
Choice A is incorrect because it results in an ungrammatical sentence. The finite verb “included” can’t be used in this way to form a subordinate clause that indicates what the Olympic committee decided. Choice B is incorrect because it results in an ungrammatical sentence. The nonfinite participle “including” can’t be used in this way to form a subordinate clause that indicates what the Olympic committee decided. Choice C is incorrect because it results in an ungrammatical sentence. The finite verb “include” can’t be used in this way to form a subordinate clause that indicates what the Olympic committee decided.