The correct answer is c) Twelve weeks.

Medical Termination of Pregnancy (MTP), also known as abortion, is a procedure that terminates a pregnancy. The safety of MTP depends on the gestational age of the pregnancy. The gestational age is measured from the first day of the woman's last menstrual period.

There are different methods of abortion available depending on the gestational age of the pregnancy. The World Health Organization (WHO) has provided guidelines regarding the safety and effectiveness of these methods.

First Trimester (Up to 12 weeks):
- MTP is considered safe up to 12 weeks of pregnancy.
- The most common method used during this period is called medical abortion or abortion with pills.
- It involves taking two medications: mifepristone followed by misoprostol.
- Mifepristone is taken orally at a healthcare facility and it works by blocking the hormone progesterone, which is necessary for the pregnancy to continue.
- Misoprostol is taken at home 24 to 48 hours later and it causes contractions of the uterus, leading to the expulsion of the pregnancy tissue.
- Medical abortion is highly effective, with success rates of up to 98% when done within the first 9 weeks of pregnancy.

Second Trimester (13 to 24 weeks):
- MTP between 13 to 24 weeks is considered relatively safe but more complex than in the first trimester.
- The method used during this period is generally surgical abortion.
- There are two main types of surgical abortion: dilation and curettage (D&C) and dilation and evacuation (D&E).
- D&C involves dilating the cervix and scraping the uterine lining to remove the pregnancy tissue.
- D&E is a similar procedure but is used for later gestational ages when the fetus is larger.
- These procedures are typically performed in a healthcare facility under local anesthesia or conscious sedation.

It is important to note that laws regarding abortion vary in different countries, and the gestational age limit for MTP may differ as well. It is always recommended to consult with a healthcare provider to understand the specific regulations and options available in a particular region.

MTP is safe untill placenta is formed.
So in second trimester MTP become risker because placenta exist.
It is safe upto 12 week ie months not 20 weeks