Explanation
The correct answer is D: Seaweed.
Agar is a gelatinous substance that is commonly used as a solid medium for culturing bacteria, fungi, and other microorganisms in laboratory settings. It is obtained from various species of seaweed, including red algae (such as Gelidium, Gracilaria, and Pterocladia) and brown algae (such as Laminaria).
Agar is an ideal medium for bacterial culture because it is stable at high temperatures and can be liquefied and poured into petri dishes while still in a liquid state. Once it cools and solidifies, it provides a semi-solid surface for bacterial growth and is resistant to degradation by most microorganisms. Additionally, it is relatively transparent, which makes it easy to observe bacterial colonies and other growth patterns.
