Okay, let's tackle this question about depot progestins. The question is asking about the route of administration for depot progestins from the March 2010 exam. First, I need to recall what depot progestins are and how they're administered.

Depot progestins are a form of long-acting progestin, often used in contraceptive methods like the depot medroxyprogesterone acetate (DMPA) injection. The term "depot" refers to a preparation that releases the drug slowly over time. Now, the route of administration is crucial here. Common routes for such medications include intramuscular, subcutaneous, oral, or transdermal.

I remember that DMPA is typically given as an intramuscular injection. The standard dose is every 12 weeks. So the correct answer should be intramuscular. Let me verify that. Yes, DMPA is administered via deep intramuscular injection, usually in the gluteal or deltoid muscles.

Now, looking at the options provided, even though they're not listed, the correct answer would be the intramuscular route. The other options would be incorrect because oral administration would not be depot, as it's a short-acting route. Subcutaneous might be possible for some drugs but not depot progestins. Transdermal patches are a different method altogether.

Clinical pearl: Remember that depot progestins like DMPA require intramuscular injection every 12 weeks for contraception. This is a high-yield fact for exams. Also, note that it's a long-acting reversible contraceptive method.

**Core Concept**
Depot progestins, such as depot medroxyprogesterone acetate (DMPA), are long-acting hormonal contraceptives requiring a specific route of administration to ensure sustained release. The term "depot" refers to a formulation designed for slow drug release at the injection site.

**Why the Correct Answer is Right**
Depot progestins are administered **intramuscularly** to allow slow absorption and prolonged therapeutic effects. The intramuscular route ensures the drug forms a depot at the injection site (e.g., gluteal or deltoid muscle), releasing progestin over weeks. This method avoids first-pass metabolism and maintains contraceptive efficacy for 12–13 weeks.

**Why Each Wrong Option is Incorrect**
**Option A:** *Oral* administration is incorrect because depot progestins require a parenteral route for sustained release; oral formulations are absorbed too rapidly.
**Option B:** *Subcutaneous* injection is not standard for depot progestins, as it does not achieve the same depot effect as intramuscular administration.
**Option C:** *Transdermal* patches are unrelated to depot progestins and are used for other hormonal therapies (e.g., estrogen).

**Clinical Pearl / High-Yield Fact**
Depot medroxyprogesterone acetate (DMPA) is a **first-line long-acting reversible contraceptive** administered **intramuscularly every 12–13 weeks**. It is contraindicated in women with undiagnosed abnormal uterine bleeding.

**Correct Answer: C. Intramuscular**

✓ Correct Answer: D. Both subcutaneous and intramuscular route