Primary batteries, unlike secondary batteries, may be:	Choose the correct choice from the following
A) 2  B) 7  C) 6  D) 8  E) 9
Explanation:   Primary batteries (disposable batteries), which are designed to be used once and discarded when they are exhausted.   Secondary batteries (rechargeable batteries), which are designed to be recharged and used multiple times.   Answer: Option 7
<result>B</result>
Primary batteries, unlike secondary batteries, may be: