1.  Which of the following statements are true about a successful call
to <tt>malloc</tt>, that is, a call that returns a non-NULL pointer?
None may be true, or more than one statement may be true.
Briefly explain your answer.
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a.  A successful call to <tt>malloc</tt> will always reduce the
number of free blocks.
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b.  A successful call to <tt>malloc</tt> may leave the number of free blocks
unchanged.
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c.  A successful call to <tt>malloc</tt> may <em>increase</em> the number
of free blocks.