The correct answer is option 4, which matches each item in List-I with the correct item in List-II. Let`s dissect each option to understand why option 4 is correct.

Option 1: This option matches List-I as follows: A - Explanation of the photoelectric effect (3), B - Discovery of a comet (2), C - Measurement of the electronic charge (4), D - Thermoelectricity (1). However, it incorrectly matches List-II, as J.J. Thomson is associated with the discovery of the electron, not the photoelectric effect. So, this option is incorrect.

Option 2: This option matches List-I as follows: A - Explanation of the photoelectric effect (3), B - Discovery of a comet (5), C - Measurement of the electronic charge (1), D - Thermoelectricity (4). However, it incorrectly matches List-II, as Robert Millikan is associated with measuring the electronic charge, not the discovery of a comet. So, this option is incorrect.

Option 3: This option matches List-I and List-II as follows: A - Explanation of the photoelectric effect (5), B - Discovery of a comet (4), C - Measurement of the electronic charge (3), D - Therm