**Core Concept**
Live oral vaccines are administered to stimulate mucosal immunity and confer protection against specific pathogens. These vaccines contain attenuated or weakened forms of the microorganism, which replicate in the host and induce an immune response without causing disease.

**Why the Correct Answer is Right**
The correct answer is a live oral vaccine, which is administered to stimulate mucosal immunity. This type of vaccine contains attenuated or weakened forms of the microorganism, which replicate in the host and induce an immune response without causing disease. The replication of the vaccine in the gut-associated lymphoid tissue (GALT) helps to induce a strong immune response against the pathogen. The live oral vaccine is an effective way to prevent diseases such as poliomyelitis, rotavirus gastroenteritis, and typhoid fever.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it is not a live oral vaccine.
**Option B:** This option is incorrect because it is not typically administered orally.
**Option C:** This option is incorrect because it is not a live oral vaccine.

**Clinical Pearl / High-Yield Fact**
Live oral vaccines are often administered to induce mucosal immunity, which is critical for preventing infections that enter the body through the gastrointestinal tract. This type of vaccine is particularly effective in preventing diseases such as poliomyelitis and typhoid fever.

**Correct Answer: C. BCG (Bacillus Calmette-Guerin) vaccine is not correct, however, the correct answer is actually not listed in the options. The correct answer is Rotavirus vaccine but it was not listed among the options. However, another example of a live oral vaccine is Rotavirus vaccine.