Answer:
An
Step-by-step explanation:
In English, nouns are accompanied by an indefinite or definite article.
Indefinite articles (a/an) refer to non-specific nouns. If it's raining and we say that we need an umbrella, we are not speaking about a specific umbrella. We'd accept any umbrella. Similarly, in the given sentence, an unusual and beautiful gift is mentioned.
The definite article (the) is used before a noun to define it as something specific (as something previously mentioned or known, something unique, or something being identified by the speaker). If the text continues talking about the said gift, the word gift will always be preceded by the definite article.