Final answer:
The correct answer is B. Omission of reagent. All of the other options can cause a false-negative reaction in Rh typing.
Step-by-step explanation:
The correct answer is B. Omission of reagent. All of the other options can cause a false-negative reaction in Rh typing. Let's break it down:
A. Rouleaux: Rouleaux refers to the stacking of red blood cells, which can interfere with the agglutination reaction in Rh typing and lead to a false-negative result.
B. Immunoglobulin coating cells: The presence of immunoglobulin (antibodies) on red blood cells can cause agglutination, resulting in a positive reaction. Therefore, it would not cause a false-negative reaction.
C. Omission of reagent: If a reagent that is necessary for Rh typing is omitted, there will be no reaction observed, leading to a false-negative result.
D. Cell suspension that is too heavy: If the cell suspension is too heavy, it can interfere with the agglutination reaction, potentially resulting in a false-negative result.
Therefore, the correct answer is B. Omission of reagent.