Step 1: Pin down the actual problem.
The statement says talented Indian children are nevertheless weak in Science and Mathematics. The course of action we pick must directly attack that specific weakness.
Step 2: Restate the test for a valid action.
A good course of action must be relevant and must plausibly improve the situation, not rest on an unstated guess about the cause.
Step 3: Weigh Action I.
Action I blames the absence of textbooks in the mother tongue. But the passage never claims language is the obstacle, so this rests on an assumption and does not clearly follow.
Step 4: Weigh Action II.
Action II points to the lack of experiment-based teaching in these subjects. Science and Mathematics are learned far better through hands-on experiments, so fixing this directly targets the weakness.
Step 5: Compare the two.
Action I is speculative, while Action II addresses a recognized cause of weak performance in these subjects, so only II is a sound action.
Step 6: Conclude.
Only Action II follows logically from the statement.
\[ \boxed{\text{Only II follows}} \]