**Core Concept**
The Complement Fixation test, also known as the Wassermann test, is a serological test used to detect the presence of antibodies against syphilis in the serum of patients. This test relies on the principle of complement fixation, where antibodies bind to antigens and activate the complement system, leading to the formation of a stable complex that can be detected.

**Why the Correct Answer is Right**
The Complement Fixation test is a type of serological test that uses the complement system to detect the presence of antibodies. In this test, the patient's serum is mixed with antigen and complement, and the presence of antibodies is indicated by the formation of a stable complex. This complex is then detected using a technique such as the precipitation reaction. The complement system is a group of proteins that play a crucial role in the immune response, including the activation of the classical pathway, which is responsible for the formation of the stable complex in the Complement Fixation test.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not describe the Complement Fixation test accurately. While it may be a type of serological test, it does not specifically use the complement system to detect antibodies.
**Option B:** This option is incorrect because it is not a type of serological test used to detect antibodies against syphilis.
**Option C:** This option is incorrect because it does not describe the Complement Fixation test accurately. While it may be a type of serological test, it does not specifically use the complement system to detect antibodies.

**Clinical Pearl / High-Yield Fact**
The Complement Fixation test is an example of a type of serological test that can be used to detect the presence of antibodies against various diseases, including syphilis. It is an important tool in the diagnosis of infectious diseases and can be used in conjunction with other diagnostic tests to confirm a diagnosis.

**Correct Answer: B. Complement Fixation test is a type of serological test used to detect the presence of antibodies against syphilis.