Step 1: Concept The Greatest Lower Bound (GLB) property states that every non-empty set of real numbers that is bounded below must have a greatest lower bound in $\mathbb{R}$.
Step 2: Meaning This greatest lower bound is formally known as the infimum of the set.
Step 3: Analysis Bounded below means there exists a number $L$ such that for all $x$ in the set, $x \ge L$. The infimum is the largest such $L$.
Step 4: Conclusion Therefore, a set bounded below is guaranteed to have an infimum.
Final Answer: (A)