To walk park, that is liked. [Syntax]

The correct answer is `さんぽする` (sanposuru). This is the plain form of the verb `さんぽします` (to take a walk). It correctly precedes `のが` to form `さんぽするのがすきです` (I like taking walks). In this structure, `の` nominalizes the verb (turns it into a noun phrase), and `が` marks this phrase as the subject of `すきです` (like). `こうえん` (park) should come before `を`. `を` is the particle marking the path or object of `さんぽする`, coming after `こうえん`. `のが` is already in place after the star. *Grammar Tip:* To say you like doing an activity, use the plain form of the verb followed by `のがすきです`. Example: ほんをよむのがすきです (I like reading books).

正解は「さんぽする」。動詞普通形。「～するのが好きです」を完成。「こうえん」は「を」の前。「を」は助詞。「のが」は既にあり不要。 文法：動詞の普通形＋「のが好きです」。