Which of the following is NOT a major component of a crawler tractor?

A crawler tractor consists of several major components that are essential for its operation in various terrains and conditions. Among these components, blades and other implements are crucial for tasks such as grading, digging, and pushing materials. The ROPS, or Roll-Over Protective Structure, is a safety feature designed to protect the operator in the event of a rollover, which is significant given the stability challenges of crawler tractors. A climate-controlled cab enhances operator comfort and focus, especially during long hours of operation in harsh weather conditions.

While hydraulic jacks can be useful tools in various applications, they are not typically considered a fundamental component of a crawler tractor itself. Instead, they serve more as ancillary equipment that may be used in maintenance or specific applications rather than being integral to the tractor's core functionality and design. This distinction clarifies why hydraulic jacks do not fit the description of a major component of a crawler tractor.