Step 1: Recall the meaning of Plan Holiday.
A Plan Holiday refers to a temporary suspension of the regular Five-Year Plans in India. During this period, instead of Five-Year Plans, Annual Plans were implemented.
Step 2: Identify the period of Plan Holiday.
India experienced the Plan Holiday during the years
\[
1966-1969
\]
This period came after the completion of the Third Five-Year Plan \((1961-1966)\) and before the beginning of the Fourth Five-Year Plan \((1969-1974)\).
Step 3: Understand the reasons for Plan Holiday.
The Plan Holiday occurred because of severe economic difficulties such as:
India-China war (1962)
India-Pakistan war (1965)
Drought and food shortages
Balance of payments crisis
Hence, the government shifted temporarily to Annual Plans instead of a long-term Five-Year Plan.
Step 4: Analyze the options.
(A) Incorrect, because there was no plan holiday between the Second and Third Plans.
(B) Correct, because the Plan Holiday occurred between the Third and Fourth Five-Year Plans.
(C) Incorrect, because regular Five-Year Plans continued during that period.
(D) Incorrect, because there was no Plan Holiday between the Ninth and Tenth Plans.
Step 5: Final conclusion.
Therefore, the Plan Holiday in India was declared between the
\[
\boxed{\text{Third and Fourth Five-Year Plan}}
\]
Hence, the correct option is (B).