Technetium, Tc, was the first element to be produced artificially — option 2.

The story. Mendeleev’s periodic table of 1869 left a gap at atomic number 43, between molybdenum and ruthenium, and he predicted an element to fill it, calling it eka-manganese. Every search of natural minerals failed. In 1937 Carlo Perrier and Emilio Segrè found it in a sample of molybdenum foil that had been bombarded with deuterons in Ernest Lawrence’s cyclotron at Berkeley. They named it technetium, from the Greek technetos, meaning artificial.

Why no stable technetium survives on Earth. Every isotope of technetium is radioactive, and the longest-lived, technetium-98, has a half-life of about 4·2 million years — far shorter than the age of the Earth, some 4,500 million years. Any technetium present when the planet formed has long since decayed. Traces do occur in uranium ores as a fission product, and it has been detected in the spectra of certain red giant stars, which is direct evidence that heavy elements are still being made inside stars.

Where it is used. The isotope technetium-99m is the most widely used radioactive tracer in medical imaging. Its half-life of about six hours is long enough for a scan and short enough to limit the dose, and it emits gamma rays without the more damaging beta particles — which makes it ideal for bone, heart and kidney scans.

Hence, the answer is Tc.