Final answer:
The Philippines has active volcanoes and a high frequency of earthquakes because it is located near the boundary of two tectonic plates.
Step-by-step explanation:
The observation that indicates that the Philippines has active volcanoes and a high frequency of earthquakes is: c. The country is near the boundary of two tectonic plates.
The Philippines is located in a tectonically active region known as the Ring of Fire, which is a zone of frequent earthquake and volcanic activity. The country is situated near the boundary of the Pacific Plate and the Philippine Sea Plate, making it susceptible to both volcanic eruptions and earthquakes.
This observation is supported by the fact that the Philippines experiences regular seismic activity and is home to numerous active volcanoes, such as Mount Mayon and Mount Pinatubo.
Learn more about Tectonic Plates