Concept:
Ludwig Wittgenstein is one of the most important philosophers of language.
His early philosophy and later philosophy contain different important ideas.
Step 1: Check Picture theory of meaning.
In his early work Tractatus Logico-Philosophicus, Wittgenstein presented the picture theory of meaning.
According to this theory, propositions picture facts.
So:
\[
A = \text{Correct}
\]
Step 2: Check Meaning as use.
In his later philosophy, Wittgenstein said that the meaning of a word lies in its use in language.
This is found in his language-game theory.
So:
\[
B = \text{Correct}
\]
Step 3: Check Defence of private language.
Wittgenstein did not defend private language.
Rather, he argued against the possibility of a purely private language.
So:
\[
C = \text{Incorrect}
\]
Step 4: Check Family resemblance.
Family resemblance is a famous idea of later Wittgenstein.
It explains how concepts may be connected by overlapping similarities rather than one common essence.
So:
\[
D = \text{Correct}
\]
Step 5: Final conclusion.
The ideas belonging to Wittgenstein are:
\[
A,\ B,\ D
\]
Hence:
\[
\boxed{\text{(D) A, B, D only}}
\]