The simple subject is the noun of the sentence.
The zoo is open seven days a week.
Answer: Zoo
You asked the question like 20 times
(hear: aud) (sea: mer/mar) (see: vid/vis) (water: aqua) (mindful: mem) (to know: sci) (sound: phon) (study: ology)
Answer:
The answer for this is C.
Explanation: