A. Voltage
B. Frequency
C. Time Duration
D. Distence

Solution

C. Time Duration

Explanation

<p><span style="letter-spacing: 0.01rem;">The duration of the echo pulse in microseconds (µs)</span></p><p><span style="font-size: 14px;">duration = pulseIn(echoPin, HIGH);</span></p><ul><li><span style="font-size: 14px;">echoPin → the pin connected to the Echo pin of the sensor</span></li><li><span style="font-size: 14px;">HIGH → measure the time the pin stays HIGH</span></li><li><span style="font-size: 14px;">duration → result is in microseconds</span></li></ul>