Q2 requires a little bit of general knowledge about the pH of various solutions (I don’t know if these are described as part of the curriculum).
HCl is a strong acid (red)
Ammonia is a relatively strong base when dissolved in water (yellow)
Lemon is a weak acid (orange)
Baking soda which is a weak base is commonly used as an oven cleaner (yellow)
Pure water is neutral (yellow)
if you arrange these in order of increasing pH:
Strong acid - red
Weak acid - orange
Neutral pH - yellow
Weak base - yellow
Strong base - yellow
Therefore this flower solution changes colour (from yellow through orange to red) as pH decreases (becomes more acidic), but doesn’t change at all as pH increases from neutral to alkaline.
The solution is a good/useful acid pH indicator but useless as a basic/alkali indicator.