Directions: Fill the blanks with most appropriate answer from the given options.

Contact your building supervisor to call a _______________ in order to fix the leak in the main pipeline.

A plumber is a tradesperson who specializes in installing and repairing water supply systems, drainage systems, and pipelines. Given the context of a 'leak in the main pipeline,' a plumber is the correct professional to address this issue. Seamstresses work with fabric and sewing, brokers facilitate transactions, and masons work with brick and stone - none of these professions handle water pipe repairs.