**Ectopic Pregnancy**

- Ectopic pregnancy is a condition in which the fertilized egg implants and grows outside the uterus, typically in the fallopian tube.
- It is a serious and potentially life-threatening condition that requires immediate medical attention.

**Occurrence of Ectopic Pregnancy**

- Ectopic pregnancy occurs in the following locations:
- Abdominal cavity: In rare cases, the fertilized egg may implant in the abdominal cavity outside the uterus. This can happen if the fallopian tube ruptures or is not present.
- Fallopian tube: The most common location for ectopic pregnancy is within the fallopian tube. The fertilized egg may get stuck or delayed in the fallopian tube and begin to grow there instead of moving into the uterus.
- Other locations: Although extremely rare, ectopic pregnancies can also occur in other locations such as the ovary or cervix.

**Explanation of Answer**

- Option 'D' (1 and 3) is the correct answer because ectopic pregnancy can occur in both the abdominal cavity and the fallopian tube.
- The abdominal cavity is a rare location for ectopic pregnancy, but it can happen if the fertilized egg does not implant in the uterus and instead implants elsewhere in the abdomen.
- The fallopian tube is the most common location for ectopic pregnancy. The fertilized egg may become stuck or delayed in the fallopian tube and begin to grow there instead of moving into the uterus.
- Option 'A' (abdominal) alone is incorrect because ectopic pregnancy can also occur in the fallopian tube.
- Option 'B' (uterus) alone is incorrect because ectopic pregnancy occurs outside the uterus.
- Option 'C' (fallopian tube) alone is incorrect because ectopic pregnancy can also occur in the abdominal cavity.
- Therefore, the correct answer is option 'D' (1 and 3), which includes both the abdominal cavity and the fallopian tube as locations for ectopic pregnancy.