Final answer:
Procter & Gamble (D) was the top company for ad spending in Europe in 2013. The provided information does not directly relate to ad spending, yet Procter & Gamble's global advertising dominance includes its spending in Europe.
Step-by-step explanation:
The company that ranked number one in terms of ad spending in Europe in 2013 was Procter & Gamble (D). While the information provided references an unrelated market dominance example in the laundry detergent sector, where Procter & Gamble was involved in the illicit coordination of market activities in France, it doesn't specifically address advertising expenditures. Nonetheless, historical data from various reporting agencies indicates that Procter & Gamble consistently ranks among the top advertisers globally and did so in Europe during 2013.