Protocista member, which shows close relations with fungi

Explanation

Water molds, or oomycetes, are protists that are closely related to fungi due to their filamentous structure and method of nutrient absorption. Unlike slime molds, which are more amoeba-like in their behavior and lifecycle, water molds exhibit true hyphal growth similar to fungi. Brown algae are primarily aquatic, photosynthetic organisms, and apicomplexans are parasitic and lack fungal-like characteristics. Thus, among the options, water molds are the group most closely related to fungi.