'Season' should be placed in the first position [as 'summer' and 'season' are meaningful when placed together]. 'Enjoy' will come in the second position as 'to' and 'enjoy' go together to make the infinitive construct ('to' + base form of the verb). 'Mangoes', which is remaining, comes at the end [conveying the meaning that 'mangoes' is the queen of fruits].
Hence, the correct answer is option (a).
Note:
An infinitive construct is a non-finite verbal form in Hebrew grammar that provides additional information about the purpose, result, or time frame of an action. It is similar to an infinitive in English, expressing actions like "to go" or "to eat".