1. **Problem statement:** Determine the type of decimal representation of the fraction $$\frac{7}{3^{2023} \cdot 2^{2021}}$$. 2. **Recall the rule for decimal representations of fractions:** - A fraction $$\frac{a}{b}$$ in simplest form has a **finite decimal representation** if and only if the denominator $$b$$ is of the form $$2^m \cdot 5^n$$ where $$m,n$$ are non-negative integers. - If the denominator contains prime factors other than 2 or 5, the decimal representation is infinite. - If the denominator contains only 2 and/or 5, the decimal is finite. 3. **Analyze the denominator:** - The denominator is $$3^{2023} \cdot 2^{2021}$$. - It contains prime factors 3 and 2. - Since 3 is not 2 or 5, the denominator is not of the form $$2^m \cdot 5^n$$. 4. **Conclusion:** - The decimal representation is infinite because of the factor 3. - Since the denominator has a prime factor other than 2 or 5, the decimal is infinite. - Also, fractions with denominators containing primes other than 2 or 5 produce infinite repeating decimals. 5. **Answer:** The fraction $$\frac{7}{3^{2023} \cdot 2^{2021}}$$ is a decimal with an infinite repeating decimal expansion. **Correct choice:** A. Số thập phân vô hạn tuần hoàn (Infinite repeating decimal)