After examining the blood group of husband and wife, the doctor advised them not to have more than one child, the blood group of the couple are likely to be:
(a) Male Rh- and male Rh+
(b) Female Rh- and male Rh+
(c) Male Rh+ and female Rh+
(d) Male Rh- and female Rh-

Options

A. Male Rh- and male Rh+
B. Female Rh- and male Rh+
C. Male Rh+ and female Rh+
D. Male Rh- and female Rh-

Answer

To determine the likely blood groups of the husband and wife based on the doctor's advice, we need to analyze the Rh factor and its implications for pregnancy.

### Step-by-Step Solution:

1. **Understanding Rh Factor**: The Rh factor is a protein that can be present on the surface of red blood cells. Individuals who have this protein are classified as Rh positive (Rh+), while those who do not are classified as Rh negative (Rh-).

2. **Potential Combinations**: The blood groups of the couple can be analyzed based on the options provided:
- (a) Male Rh- and Male Rh+
- (b) Female Rh- and Male Rh+
- (c) Male Rh+ and Female Rh+
- (d) Male Rh- and Female Rh-

3. **Analyzing Each Option**:
- **Option (a)**: Male Rh- and Male Rh+ - This combination does not involve a female, so it is not applicable.
- **Option (b)**: Female Rh- and Male Rh+ - This combination is critical because if the female is Rh- and the male is Rh+, their first child could be Rh+. If the child is Rh+, the mother may develop antibodies against Rh factor during childbirth, which could affect subsequent pregnancies.
- **Option (c)**: Male Rh+ and Female Rh+ - Both parents are Rh+, so there is no risk of the mother developing antibodies against Rh factor. This option does not explain the doctor's advice.
- **Option (d)**: Male Rh- and Female Rh- - Both parents are Rh-, so there is no risk of Rh incompatibility. This option also does not explain the doctor's advice.

4. **Conclusion**: The only combination that explains the doctor's advice against having more than one child due to potential complications is option (b) - Female Rh- and Male Rh+. In this scenario, the first child could be Rh+, leading to the mother developing antibodies that could harm a second Rh+ child.

### Final Answer:
(b) Female Rh- and Male Rh+

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