I need the entire sentence for context before I can answer the question. All of these options could be a subject, but you need to give context.
Answer:
Where's the excerpt? did you forget to add the picture?
foot
Two or more syllables that together make up the smallest unit of rhythm in a poem. For example, an iamb is a foot that has two syllables, one unstressed followed by one stressed. An anapest has three syllables, two unstressed followed by one stressed.
