A suitable title for the passage is
( b ) is wrong because it states that the game is an example for mindfulness. The whole passage talks about the emotions in that game which can be used to explain mindfulness.
The game itself is not an analogy for mindfulness.
( d ) is also wrong because solitaire is not a game of emotions and mindfulness . It is a game of cards filled with emotions and mindfulness.
It is a very close call between ( a ) and ( c )
The whole passage is about the plethora of emotions in this game. It is more like a gambling of emotions in a cards game. One emotion comes and goes which is then followed by a contrasting emotion coming up and going. It is more like a gambling of emotions in the author’s mind when he is playing the game of solitaire. So the better answer is (a) rather than (c ). It is more a narrative passage rather than a descriptive passage.
Option (a) is an apt heading for a narrative passage and ( c ) is more of a title for a descriptive passage.
So( a ) is the answer.