The correct answer is option 3: Bacteria. Bacteria reproduce at a faster rate compared to the other groups of organisms mentioned. Bacteria have a very short reproduction cycle, with some species being able to divide and reproduce every 20 minutes under optimal conditions. This rapid rate of reproduction allows bacteria populations to grow exponentially in a short period of time.

On the other hand, algae, fungi, and protozoa generally have longer reproduction cycles compared to bacteria. Algae reproduce through cell division or fragmentation, which may take longer than the reproduction process of bacteria. Fungi reproduce through spores that can take time to develop and mature. Protozoa reproduce through various methods such as binary fission, budding, or sexual reproduction, and their reproduction rates can vary depending on the species.

Therefore, among the given options, bacteria are known for their faster reproductive abilities.