Internal combustion engines with two or more strokes are called __ engines, meaning the pistons move in a back and forth motion within the cylin a. Rotary motion b. Recurring motion c. Multi-cylinder motion d. Reciprocating motion

## Step 1<br />The problem is asking us to identify the type of motion that the pistons in an internal combustion engine with two or more strokes exhibit. The options provided are: a. Rotary motion, b. Recurring motion, c. Multi-cylinder motion, and d. Reciprocating motion.<br /><br />## Step 2<br />Let's analyze each option:<br />- Rotary motion refers to a circular movement around a central axis. This is not the type of motion that pistons in an internal combustion engine exhibit.<br />- Recurring motion is not a standard term used in the context of engine mechanics.<br />- Multi-cylinder motion refers to an engine with multiple cylinders. This term does not describe the type of motion of the pistons.<br />- Reciprocating motion is the type of motion where an object moves back and forth in a straight line. This is the type of motion that pistons in an internal combustion engine exhibit.<br /><br />## Step 3<br />Based on the above analysis, the correct answer is d. Reciprocating motion.