Final answer:
A study of landmarks in downtown Houston would address the theme of Place in the 5 themes of geography because landmarks contribute to the unique character and identity of that location.
Step-by-step explanation:
When considering the 5 themes of geography with respect to a study of landmarks in downtown Houston, the theme that would be addressed is (b) Place. The theme of Place refers to the specific human and physical characteristics of a location. Landmarks are significant because they contribute to the unique aspects of a place, including its physical appearance, culture, and history, which differentiates one place from another. These can include architectural styles, monuments, plazas, and other noteworthy locations that define the character of downtown Houston.
Studying landmarks is closely associated with the character of a place, which aligns with WG.5A from the learning objectives that emphasizes analyzing how the character of a place is related to its political, economic, social, and cultural elements. Thus, it investigates how landmarks contribute to the cultural identity and character of downtown Houston within the context of the urban environment and geographical location.