Correct Answer (1) TiO

Why:

When an element is written such as titanium(II) the number in the parentheses is usually referring to the oxidation state.  So in this case we are looking at Ti²⁺ combining with Oxygen to make Titanium (II) Oxide.

The periodic table is arranged in groups that also give us an idea of how many valence electrons an element has.  The "tall" groups (vertical lines) can be counted, beginning with Hydrogen, one thru eight correlating to how many valence electrons are available. By this method we know Oxygen has 6 valence electrons and wants two more to complete itself with 8.

Titanium (II) has an oxidation state of +2 and will readily share with the Oxygen making this the most stable compound for it to form.  Answer (2) has two oxygen atoms therefore needing 4 electrons and will typically only form with Titanium (IV).  Answer (4) has three Oxygen needing 6 electrons and two Titanium (III) will join to complete that.  Answer (3) would need to be Titanium (I) and that doesn't occur naturally.

Answering this question:

The only way to answer this question with 100% certainty is to know what titanium (II) oxide is.  If you don't recognize it from memory you may have a better shot at the correct answer by looking at Nomenclature.  Answer (2) should be something like Titanium dioxide.  Answer (1) is the only straightforward titanium oxide.  While this approach is better than nothing, it will not always steer you into the right answer in chemistry.