Explanation:

In Microsoft Word, the keyboard shortcut $\text{Ctrl} + \text{H}$ opens the 'Find and Replace' dialog box with the 'Replace' tab active, allowing users to find specific text and replace it. Option (1) $\text{Ctrl} + \text{R}$ is for right-aligning text. Option (2) $\text{Ctrl} + \text{N}$ is for creating a new document. Option (4) $\text{Ctrl} + \text{F}$ opens the 'Find' dialog or navigation pane, but not directly the 'Replace' function as requested.