C Question

Consider the two snipits used to make a struct


//T1
struct b *create_b(...)
{
  struct b *a = malloc(sizeof(struct b));
  ...
  return a;
}

//T2
struct b *create_b(...)
{
  struct b a;
  ...
  return &a;
}

would T2 produce memory errors later on in a program if used a lot? How would it know to when to cleanup a?

Use of persistent local variables considered fucking evil.