**Introduction:**
In genetics, the cross between pure red and pure white flowered pea plants is a classic example of Mendelian inheritance. By analyzing the offspring of this cross, we can determine the ratio of red to white flowers and understand the underlying genetic principles at play.

**Mendelian Inheritance:**
Mendelian inheritance refers to the transmission of traits from parents to offspring according to certain principles proposed by Gregor Mendel. These principles include the law of segregation and the law of independent assortment.

**Law of Segregation:**
The law of segregation states that during the formation of gametes (sex cells), the two alleles for a trait segregate or separate from each other, so each gamete receives only one allele.

**Law of Independent Assortment:**
The law of independent assortment states that different pairs of alleles segregate independently of each other during the formation of gametes. This means that the inheritance of one trait does not influence the inheritance of another trait.

**Crossing Pure Red and Pure White Flowered Pea Plants:**
When pure red (RR) and pure white (rr) flowered pea plants are crossed, the offspring are called the first filial generation or F1 generation. The F1 generation plants are all heterozygous (Rr) for flower color.

**Punnett Square Analysis:**
To determine the possible genotypes and phenotypes of the F1 generation, we can use a Punnett square. The Punnett square for this cross would be:

R r
R RR Rr
r Rr rr

From the Punnett square, we can see that there are two possible genotypes in the F1 generation: RR (red) and Rr (red). Therefore, all the F1 generation plants will have red flowers.

**F1 Generation Ratio:**
Since all the F1 generation plants have the genotype Rr (red), the ratio of red to white flowers in the F1 generation is 100% red and 0% white. Therefore, option (d) "All red" is the correct answer.

**Conclusion:**
By applying the principles of Mendelian inheritance and analyzing the Punnett square, we can determine that the F1 generation of the cross between pure red and pure white flowered pea plants will result in all red-flowered plants. This outcome is due to the dominance of the red flower color allele (R) over the white flower color allele (r).