Symbol Definitions and Analysis

First, let's establish the meaning of the symbols and how to interpret the chained expressions based on the problem's logic.

• A + B means A is younger than B (A < B).


• A - B means A is older than B (A > B).


• A chained expression like X + Y + Z is interpreted as a continuous sequence: X < Y and Y < Z, which simplifies to the overall age order X < Y < Z.

Evaluating the Expressions

• 
  The Given Expression (X + Y + Z): As defined above, this expression means X is the youngest, followed by Y, and Z is the oldest (X < Y < Z).
  


• 
  Option (B) Z - Y - X: According to the rules, this expression is interpreted as Z > Y and Y > X, which simplifies to the overall age order Z > Y > X.
  

The age order X < Y < Z is identical to the order Z > Y > X. Therefore, the two expressions are logically equivalent. The other options result in different, contradictory orderings.

Final Answer: The correct option is (B) Z - Y - X.