Local school does not have proper toilet facilities​

Contrast

Explanation:

The sentence you were given is the following:

The duck was delighted with his new toy and immediately began to experiment with it, but within moments his mood changes from joyful to despondent.

The options you were given are:

When you're unsure about what a certain word means, you can try to figure out its meaning based on the context - words, phrases, and sentences that surround it.

The context clue that can help us understand the meaning of the word despondent is contrast. The first clause describes how delightful the duck is, and the second is introduced with the conjunction but. But is a contrast conjunction - it is used to connect ideas that oppose each other. The duck was happy, but its mood suddenly changed. We can assume that the word despondent means the opposite of happy or something close to that.

Another tool that can help us find out what a word means is a dictionary - an alphabetically arranged listing of words that contains different information about them, such as their definitions, examples, origin, pronunciation, etc. If we look up the word despondent in a dictionary (e.g. Merriam-Webster Dictionary), we can confirm what it means exactly: feeling or showing extreme discouragement, dejection, or depression.