What is the simplest way we might detect life on an extrasolar planet?

Question

Quizplus · Accepted Answer

Analyzing the spectrum of reflected light from the planet can reveal the presence of certain molecules, like oxygen or methane, which are produced by living organisms. This is known as biosignature detection and is the most promising method for detecting life on extrasolar planets with our current technology. Option A (listening for radio signals) assumes the existence of an advanced civilization with communication technology, which is highly unlikely, while option B (waiting for aliens to visit us) is impractical and unrealistic. Option D (sending a probe) is currently beyond our technological capabilities, and it would take decades or even centuries to receive the data from the probe.

What Is the Simplest Way We Might Detect Life on an Extrasolar