**Core Concept**
The Influenza trivalent vaccine is a type of vaccine designed to protect against three specific strains of the influenza virus. The vaccine typically contains two influenza A strains and one influenza B strain. The components of the vaccine are carefully selected to match the circulating strains of the virus during a particular flu season.

**Why the Correct Answer is Right**
The Influenza trivalent vaccine typically contains two influenza A strains (one H1N1 and one H3N2) and one influenza B strain. These strains are selected based on the World Health Organization's recommendations and are designed to provide protection against the most common circulating strains of the virus. The vaccine stimulates the body's immune system to produce antibodies against these specific strains, providing immunity against future infections.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the Influenza trivalent vaccine typically contains two influenza A strains and one influenza B strain, making it a component of the vaccine.
**Option B:** This option is incorrect because the Influenza trivalent vaccine typically contains one influenza A H1N1 strain and one influenza A H3N2 strain, but it may not contain a B/Victoria lineage strain every year.
**Option C:** This option is incorrect because the Influenza trivalent vaccine typically contains one influenza B strain, which is either a B/Yamagata lineage strain or a B/Victoria lineage strain.
**Option D:** This option is incorrect because the Influenza trivalent vaccine typically contains two influenza A strains and one influenza B strain, making it a component of the vaccine.

**Clinical Pearl / High-Yield Fact**
The Influenza trivalent vaccine is updated annually to match the circulating strains of the virus, which can change from year to year. The vaccine is typically available in two forms: a traditional injectable vaccine and a nasal spray vaccine. The nasal spray vaccine is not recommended for individuals with certain underlying medical conditions.

**Correct Answer: B. B/Victoria lineage strain