Step 1: Understand the nature of concentrated nitric acid.
Concentrated nitric acid \((HNO_3)\) is a strong oxidizing agent.
When phosphorus reacts with concentrated nitric acid, phosphorus gets oxidized while nitric acid gets reduced.
Step 2: Determine the oxidized product of phosphorus.
Elemental phosphorus has oxidation state:
\[
0
\]
During the reaction, phosphorus is oxidized to phosphoric acid:
\[
H_3PO_4
\]
Now calculate the oxidation state of phosphorus in \(H_3PO_4\):
Let oxidation state of phosphorus be \(x\).
\[
3(+1)+x+4(-2)=0
\]
\[
3+x-8=0
\]
\[
x=+5
\]
Thus, phosphorus changes from:
\[
0 \longrightarrow +5
\]
Hence, phosphorus undergoes oxidation and forms:
\[
H_3PO_4
\]
Step 3: Determine the reduced product of nitric acid.
In concentrated nitric acid, nitrogen has oxidation state:
\[
+5
\]
Concentrated \(HNO_3\) generally gets reduced to nitrogen dioxide \((NO_2)\).
Now calculate oxidation state of nitrogen in \(NO_2\):
\[
x+2(-2)=0
\]
\[
x-4=0
\]
\[
x=+4
\]
Thus, nitrogen changes from:
\[
+5 \longrightarrow +4
\]
Hence, \(HNO_3\) is reduced to:
\[
NO_2
\]
Step 4: Write the reaction.
The reaction can be represented as:
\[
P + HNO_3 \longrightarrow H_3PO_4 + NO_2 + H_2O
\]
Thus, the oxidized product is \(H_3PO_4\) and the reduced product is \(NO_2\).
Step 5: Match with the given options.
The correct option is:
\[
(1)\; H_3PO_4,\; NO_2
\]
Step 6: Final conclusion.
Hence, the correct answer is:
\[
\boxed{H_3PO_4,\; NO_2}
\]