Select the most appropriate option to substitute the underlined segment in the given sentence.
Amit is also a chip off the old block like his brother, Tandon.

The correct option is: resembling his parents in character and appearance.

Step-by-step Explanation:
1. Identify the Idiom: The underlined phrase in the given sentence is "chip off the old block".
2. Define the Idiom: The expression "a chip off the old block" is a common English idiom used to describe a person who is very similar to one of their parents in terms of character, behavior, personality, or physical appearance.
3. Evaluate the Options:
- getting ready for the future endeavours: This refers to preparing for future tasks, which is unrelated to similarity to parents.
- planning things ahead neatly: This describes being organized and planning in advance, which is incorrect.
- talking to others tough like a stone: This refers to speaking in a harsh or rigid manner, which does not match the idiom's meaning.
- resembling his parents in character and appearance: This directly aligns with the definition of the idiom "a chip off the old block".
4. Conclusion: Substituting the idiom with its meaning, the sentence reads: "Amit is also resembling his parents in character and appearance like his brother, Tandon." This makes logical sense in the context of comparing family traits. Therefore, this option is the correct substitute.