The correct answer is C. If it is a nice day, we will go to the beach.
Step-by-step explanation:
In language, the conditional refers to a grammatical mood used to express events that depend on one condition or situation. This can be identified by the use of "if", and modal verbs such as would, might or could. On the other hand, the subjunctive mood is used to express a hypothetical situation; this means a situation that has not happened, and it is not likely to occur.
According to this, it is " If it is a nice day, we will go to the beach" the sentence that is conditional but not subjunctive. This can be explained as this sentence uses "if" and states one situation that depends on another, and therefore this sentence is conditional. However, compared to others that use "If I were" or "If I had" this is not a hypothetical situation but will occur, which means the speaker will go to the beach if the condition is fulfilled, and therefore it is not subjunctive.