A scientific theory is. A. A well-tested explanation for a broad set of observations
B. A well-tested explanation for a widely accepted hypothesis
C. A proven explanation for the results of multiple experiments
D. A hypothesis that has stood the test of time

B. A well-tested explanation for a widely accepted hypothesis

Explanation:

This is true about a scientific theory going by the fact of it being a well tested explanation. For example, in one of the Newtons law of motion which he stated to be "To every action, there is equal and opposite reaction", the hypothesis has been known till he was able to offer a well tested explanations with calculations showing that, it was actually true.

  the grams     of oxygen gas   that can be produced     is 20.6   grams of o₂

calculation

2liclo₃ →   2 licl + 3 o₂

step 1:   find the moles of liclo₃

moles = mass÷ molar mass

from periodic table the molar mass of liclo₃ =6.9 +35.5   +(16 x3) =90.4 g/mol

moles=38.7 g÷90.4 g/mol=0.4281   moles

step 2:   use the   mole ratio   to calculate the moles of o2

from equation above, liclo₃: o₂   is 2: 3  

therefore the moles of   o₂=0.4281 moles x3/2 =0.6422   moles

step 3: find mass   of o₂

mass= moles x molar mass

from periodic table the   molar mass of   o₂ = 16 x2= 32 g/mol

mass=0.6422   moles   x   32 g/mol = 20.6 grams of o₂

and 1and 1