Answer: car | truck
Explanation: The pipe (|) symbol used can be used in regular expression to simply imply OR. This means when used in between expression, can be used to search for all matches of the strings in which it stands in between. In the scenario above, If the pipe symbol is located in between the two strings, such as [ cars | trucks], the expression returns possible occurrence of the strings cars and trucks. It may also be used to locate and return the occurrences of more than 2 strings, such as; string1 | string2 | string3