Q1: Hydrographic surveys deal with the mapping of

ANS:A - large water bodies

Hydro means water, so both small and large water bodies can be studied in the hydrographic survey.
We may get a doubt that even the canal system is a water body. But the canal system is a type of water body.
When a water body is given as an option we can go for option A, i.e., large water bodies. Hydrographic survey is the science of measurement and description of features which affect maritime navigation, marine construction, dredging, offshore oil exploration/offshore oil drilling and related activities. Hydrographic survey is the science of measurement and description of features which affect maritime navigation, marine construction, dredging, offshore oil exploration/offshore oil drilling and related activities. Hydro means water and graphy mean measurement, canal also contains water but the area is small than large water bodies for a survey, so I agree A is the right answer. Hydrographic survey is the science of measurement and description of features which affect maritime navigation, marine construction, dredging, offshore oil exploration/offshore oil drilling and related activities.

Strong emphasis is placed on soundings, shorelines, tides, currents, seabed and submerged obstructions that relate to the previously mentioned activities. The term hydrography is sometimes used synonymous to describe maritime cartography, which in the final stages of the hydrographic process uses the raw data collected through hydrographic survey into information usable by the end user.

Hydrography is collected under rules which vary depending on the acceptance authority. Traditionally conducted by ships with a sounding line or echo sounding, surveys are increasingly conducted with the aid of aircraft and sophisticated electronic sensor systems in shallow waters.