Challenge on Some Definition on Formal Language & Recursive & Automata

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We know set $A$ is countable if $A$ is finite or in a one-to-one mapping to natural numbers.

Suppose $\Sigma$ be an arbitrary finite alphabet.

I summarize my inference:

$a)$ Each arbitrary Language on $\Sigma$ is Countable. (I think this is True)

$b)$ the set of all language from $\Sigma$ is Countable.(I think this is False)

$c)$ for Each arbitrary Language on $\Sigma$ we have a generative formal grammar. (I think this is False)

$d)$ Each arbitrary Language on $\Sigma$ that can be generated by formal grammar, is recursive. (I think this is True)

anyone could help me, and maybe correct me?