GATE CS 1987 Q1-xiv — Parsing (LL, LR)

An operator precedence parser is a special type of shift-reduce parser, which belongs to the class of bottom-up parsers.

Key points about operator precedence parsing:

• It is used for a subclass of grammars called operator grammars, where no production has $\epsilon$ on the right-hand side, and no two non-terminals are adjacent.
• It works by identifying the "handle" (the substring to be reduced) using precedence relations ($\lessdot$, $\doteq$, $\gtrdot$) between adjacent terminals in the input.
• Like all shift-reduce parsers, it builds the parse tree from the bottom (leaves/tokens) up to the top (start symbol).

Thus, it is a bottom-up parser, making Option A the correct choice.